1. Field of the Invention
This invention relates generally to hangers for suspending pipes, tubes, ducts and other apparatus from floor joists, beams and the like. More particularly, the invention pertains to a universal bracket for use with commercial beam clamps and the like, by which spiral pipe may be suspended in commercial and home applications.
2. State of the Art
Various pipe hanger designs have been used for many years. Sometimes, a pipe-fitter will custom make hangers appropriate for the particular pipe size, pipe weight, working space and suspending distance. For example, a hanger band of thin metal encircling a pipe is bent at each end to form matching vertical flanges and a horizontal portion. Holes are formed in the flanges for bolting them together, an in the horizontal portion so that a nut may be screwed onto a vertical threaded rod passed through the horizontal portion. The resulting hanger requires a substantial number of bending steps. Attachment of the nut to the vertical support rod may be difficult because of the limited space for inserting fingers or a tool to turn the nut. Furthermore, the nut must be turned while the weight of the pipe is applied to it, leading to the stripping of threads. The final step of attaching the nut determines the installed pipe elevation; thus, pre-setting of the pipe elevation to blueprint specifications cannot be done. In addition, such pipe hangers tend to bend under pipe weight to a lowered position.
One recurring difficulty in hanging pipes is that the space for working on the pipe may be extremely cramped, and it may be necessary to support the pipe in the desired position while attempting to hold a bolt and a small nut in one's fingers, hold several parts of the hanger so that holes in each are aligned, inserting the bolt and threading the nut onto the bolt. It may be necessary to accomplish these actions with one's arms fully extended. It is easy to drop one or more of the parts while attempting to manipulate them in unison.
Various attempts have been made to provide apparatus and methods for suspending pipes more quickly, more easily, more precisely and at lower cost.
U.S. Pat. Nos. 1,362,244 and 1,362,245 of Farley depict an early pipe hanger comprising a perforated flexible strap bolted to a perforated stirrup strip which is passed around a pipe. Adjustment of suspension height is limited to the particular hole spacing.
U.S. Pat. No. 4,004,768 of Evans et al. discloses a tailpipe hanger for automobiles. A flexible strap supports a pair of parallel multi-member flexible shock- and sound-absorbing strap members. The hanger has a purpose which differs from that in building construction, is inapplicable to large heavy piping, and complex in manufacture.
U.S. Pat. No. 4,004,767 of Chilton shows a pipe hanger with an upper hanger screwed to a beam and a lower pipe supporting saddle which may be quickly attached to the hanger by rotation.
A pipe hanger for attaching a pipe in close proximity to a wall is shown in PCT Publication No. WO 96/18057. This hanger is not adaptable for suspending a pipe significantly below a beam or ceiling, and once installed, is not adjustable.
In U.S. Pat. No. 4,113,286 of Kennedy, Jr., a pipe hanger is shown with three legs which clamp together to compress a pipe encircling gasket.
European Patent Publication No. 0 118 584 of Hurtubise shows a hanger for hanging multiple pipes. It is not applicable to large diameter pipes, and unless balanced, will tend to bend and loosen the support rod from its upper attachment.
U.S. Pat. No. 5,219,427 of Harris, U.S. Pat. No. 3,623,686 of Dupuis, and U.S. Pat. No. Design 330,672 of Wilkinson, III show a clevis type pipe hanger which is attached to a vertical threaded rod by a simple nut, and with a horizontal bolt holding a lower yoke to an upper yoke.
In U.S. Pat. No. 4,047,683 of Takeuchi, a pipe hanger includes a closed loop element formed of a strip of sheet metal and having slots into which formed ends of a hanger band may be temporarily inserted and held pending full tightening of a screw fastener. A specially made nut is rotatably mounted atop the closed loop element with a thin flange, the latter representing a weak link in the entire hanger. Manufacture of the closed loop element requires cutting of the sheet metal strip, punching of five holes in the strip, bending the strip (six bends), molding and threading the nut, inserting the nut end in a topmost (horizontal) hole, placing a washer over the nut end, and crimping the rim of the nut end about 360 degrees within the small space in the closed loop. The manufacture requires many steps and is time consuming and expensive.
In U.S. Pat. No. 4,019,705 of Habuda, Sr. et al., a pipe hanging apparatus includes a specially made rotatable nut with a flanged end, or alternatively, a standard threaded nut rotatable relative to the collar. Manipulation of the nut e.g. with a wrench while attaching it to a support rod is difficult because of the limited space.
U.S. Pat. No. 5.624,217 of Hungerford, Jr. discloses a channel connector with two opposed, spaced apart lugs for suspending a pipe from a structural channel.
U.S. Pat. No. Design 377,750 of Hubbard shows a simple elongate hanger comprising a formed handle with a hole for passing a pipe therethrough. Such a hanger is not applicable to a large diameter pipe and must be preinstalled on a pipe prior to hanging.
In U.S. Pat. No. 950,978 of Williams, a pipe hanger is shown in which a supporting small diameter pipe has a pipe cap on its lower end with a downwardly projecting lug with a hole through it. A bolt is passed through ends of the pipe cradle band and the lug.
The above indicated prior art references show pipe hanging devices which are complex and difficult to manufacture in high volume, or are not applicable to typical spiral pipe sizes used in industrial and home construction. A pipe hanger bracket is needed which works with any beam clamp or other clamp having a continuously threaded support rod, and also cooperates with a support band with simple bent ends having a hole. In addition, a pipe hanger bracket is needed to reduce the number of fasteners (nuts and bolts), such being easily lost in a construction area. In addition, a pipe hanger bracket is needed which is easier and less expensive to construct, is stronger than prior art brackets, is easier to install with accuracy, and may be preset to a desired pipe elevation.